An electronic musical apparatus which detects reflected light to control the musical tone signal is known. Such a device was disclosed in Japanese Laid-Open Utility Model Application Publication Number SHO 58-195296.
Japanese Laid-Open Utility Model Application Publication Number SHO 58-195296 discloses attaching a light quantity detection apparatus in order to detect and sense the amount of ambient light outside an electronic musical apparatus. It reacts to the amount of light that has been sensed by the light quantity detection apparatus and controls parameters that are related to the musical tone (hereinafter, simply referred to as "parameters") such as the musical interval, timbre and volume.
However, in the device disclosed in Japanese Laid-Open Utility Model Application Publication Number SHO 58-195296, the amount of light is detected by a single light quantity detection apparatus, and there is no disclosure in Japanese Laid-Open Utility Model Application Publication Number SHO 58-195296 of the detection of a plurality of light quantities.
In addition, U.S. Pat. No. 5,045,687 discloses that a space is irradiated with light such as infrared light, mutually different sound pitches are assigned in advance to the multiple number of light beams reflected from the specified objects in the space, said multiple number of reflected light beams are detected and musical tone signals are produced that possess pitches which conform to the reflected light beams that have been detected.
However, in the system disclosed in U.S. Pat. No. 5,045,687, if a plurality of reflected light beams are detected, the device controls the musical tone signal based only on one of the reflected light beams, the one that is detected first. U.S. Pat. No. 5,045,687 does not disclose that controlling musical tone signals by means of the joint action of a multiple number of reflected light beams.